package util;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class InputFilter implements Filter {

	  public void init(FilterConfig filterConfig) throws ServletException {
	        
	    }

	    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
	        HttpServletRequest req = (HttpServletRequest) request;
	        HttpServletResponse resp = (HttpServletResponse) response;
	        String userId = req.getParameter("userId");
	        
	        if(userId.matches("^[0-9].*$") || userId.contains(" ") || userId.length() < 8 || userId.length() > 16) {
	            resp.getWriter().println("Invalid User ID");
	            return;
	        }
	        chain.doFilter(request, response);
	    }

	    public void destroy() {
	        
	    }

}
